Andrew Harper doesn’t get much sleep. There just aren’t enough hours in the day. At 48, he’s devoted more than half of his life to aiding refugees, and years ago he turned his attention to Jordan, where he serves as a top liaison between UNHCR, the U.N.’s refugees agency, and the Hashemite Kingdom. Today, he’s based in Amman but is frequently near Mafraq along the Syrian border at Zaatari, the camp he helped plan and open one year ago.

Initially carved out of the desert as a short-term refuge for up to 60,000 refugees, Zaatari has become Jordan’s fourth largest city and the world’s second largest refugee camp behind Dadaab in eastern Kenya. Of the estimated 650,000 Syrians who have crossed into Jordan, 350,000 have filtered through Zaatari and 150,000 call it home. The influx, sometimes 3,000 refugees per day, is unprecedented.

“All of the worst-case scenarios that we had for the situation in Syria and the number of people coming into Jordan were continually passed,” Harper said with a thick Australian accent in a recent phone interview with TIME. U.N. Secretary-General Ban Ki-moon said recently that 100,000 have been killed in Syria since March 2011; nearly 80,000 have been killed in the past year alone. An estimated 1.7 million people have fled the country and millions more remain internally displaced.

Harper calls the impact of the civil war “terrifying.” Rebel fighters have turned on one another as they battle the army and allies of Syrian leader Bashar Assad, and an indecisive international community — wary of arming the opposition — has largely stayed out of the conflict. Those who make it out of Syria have become the responsibility of neighboring Jordan, Lebanon, Turkey, Iraq and Egypt.

Zaatari is the best-known refugee camp for Syrians, and since its planning there has been criticism. “People were saying, ‘Look, you’re wasting your time and money building a camp because Syrians will never put themselves to live in a tented camp in the middle of the Jordanian desert. It just won’t happen,’” Harper recalls. “And I was saying look, whatever you want to say, we have to do it. We have to be prepared for the unknown.”

In his role, Harper works closely with the Jordanian government, which he updates on border crossings, refugee documentation and new arrivals at Zaatari. He says Jordan was initially opposed to a camp. Calling Syrians their brothers and sisters, Jordan allowed refugees to go directly into major cities and already desperate communities. That influx of what Harper calls an “anonymous, vulnerable population” aggravated underlying social tensions: public resources were stretched thin, classrooms became overcrowded and prices for food jumped, making it more difficult for Jordanians to feed their own families, let alone others.

After the camp opened to relieve the pressure on Jordanian communities, it began to swell. So too have the problems. A Brookings Institution investigation called Zaatari “an awful place, with serious security problems” like widespread looting, prostitution and too few classroom seats for children. Many of the standard-issue white tents are now stained by sand. Most of the basic goods or services are available, but daily operations cost about $500,000. The effort is notoriously underfunded, Harper says, but despite the hardships at Zaatari, he thinks its residents fare better than others in the region.

That doesn’t make the future any less daunting. Camp officials know they can’t keep everyone happy, and there are some refugees who have decided to try their luck again in Syria. Harper wants to ensure the basics are “done right,” efficiently and transparently, given the harsh environment and limited resources. To do that, he has turned to technology. Harper uses Twitter for public information dissemination, satellite imagery shows how the camp grows and points out empty space and potential flood risks, and biometrics (iris scans) are used both to register refugees and prevent identity theft in the cash-assistance program.

As the war rages, Zaatari is just about full, and Harper says those advances have aided in planning and building another camp capable of housing 130,000 refugees. That location in al-Azraq, east of Amman, could be operational if needed within a month. “If we’re thrown the challenge, we will deal with it,” he says. “It will cost a lot of money. It will involve a lot of logistics. We will struggle, but we will do it.”

That’s a lot of pressure when much of the world assumes refugees are safe once they have crossed out of Syria. The high visibility of the camp — two of its most recent visitors were U.S. Secretary of State John Kerry and Japan’s Foreign Minister Fumio Kishida — has kept Harper’s team, NGOs and aid groups “on our toes” with little room for mistakes. It keeps them nimble and transparent and, they hope, ready to tackle whatever may come next.

Harper aims for the camp to eventually close, but that day is likely a long way off. “We need to make sure that once the refugees go home, Insha’Allah, that Jordan’s overall infrastructure is not worse off,” he says. That’s a tall order when those fleeing the hell just a few miles north keep coming. But Harper thinks they can pull it off. “We’re not going to fail,” he says. “This is our mandate.”